/Engine/Source/Editor/UnrealEd/Public/Editor.h
Delegate type for when a user starts dragging something out of content browser (can be multiple assets)
typedef TMulticastDelegate_TwoParams< void, const [TArray](API\Runtime\Core\Containers\TArray)< [FAssetData](API\Runtime\CoreUObject\AssetRegistry\FAssetData) > &, class [UActorFactory](API\Editor\UnrealEd\ActorFactories\UActorFactory) * > FOnAssetDragStarted